Descriptions of such networks and systems can be found in the litterature such as in particular in Technical Specifications published by standardisation bodies. Examples of standardisation bodies include 3GPP (3rd Generation Partnership Project) . . . etc.
In such systems, a terminal (such as for example Mobile Station MS or User Equipment UE) has access to communication services via an Access Network, enabling various user services and applications.
An example of Access Network is the IP Connectivity Access Network (IP-CAN) providing IP connectivity, enabling various IP-based user services and applications. Examples of IP-CAN include GPRS (as specified in particular in 3GPP TS 23.060) and Evolved Packet Core (EPC) (as specified in particular in 3GPP TS 23.401). IP-CAN includes network nodes such as for example Serving GPRS Support Nodes (SGSN), Serving Gateway (S-GW), Gateway GPRS Support Node (GGSN) and PDN Gateway (P-GW).